import pca9685
import math
class Servos:
	def __init__(self, i2c, address=0x40, freq=50, min_us=600, max_us=2400, degrees=180):
		self.period = 1000000 / freq
		self.min_duty = self._us2duty(min_us)
		self.max_duty = self._us2duty(max_us)
		self.degrees = degrees
		self.freq = freq
		self.pca9685 = pca9685.PCA9685(i2c, address)
		self.pca9685.freq(freq)
	def _us2duty(self, value):
		return int(4095 * value / self.period)
	def position(self, index, degrees=None, radians=None, us=None, duty=None):
		span = self.max_duty - self.min_duty
		if degrees is not None:
			duty = self.min_duty + span * degrees / self.degrees
		elif radians is not None:
			duty = self.min_duty + span * radians / math.radians(self.degrees)
		elif us is not None:
			duty = self._us2duty(us)
		elif duty is not None:
			pass
		else:
			return self.pca9685.duty(index)
		duty = min(self.max_duty, max(self.min_duty, int(duty)))
		self.pca9685.duty(index, duty)
	def release(self, index):
		self.pca9685.duty(index, 0)
